Inadequate bowel preparation may lead to a longer colonoscopy, and to an inability to identify lesions. PEG can provide a rapid orthograde peroral approach to colonic lavage without producing significant fluid or electrolyte changes. Thus PEG is now commonly used for bowel preparation. However, large amounts and unsatisfactory taste of PEG solution are generally poorly tolerated. a new low volume PEG-based bowel cleansing agents became available at foreign countries. Although several studies reported the efficacy and improved compliance of these low volume PEG plus ascorbic acid solution for colonoscopy, but result in Korean patients was not-recognized.